In master version from github (and in future 0.6.7) you go to Settings - Default server - Add remote server. Enter hostname/ip and you're done.
Keep in mind that default server is disabled if your View mode setting is set to Combined. Set that to default server until you enter your remote server, then you can set to combined again if you want it.

Combined - option in View mode will show sections for all your servers in the Default Server list combined in the main Plex menu. Awesome feature!

In the most recent version, the adding, modifying and removing of remote servers has been moved out of the "default server" and into it's own settings panel.

...Keep in mind that default server is disabled if your View mode setting is set to Combined. Set that to default server until you enter your remote server, then you can set to combined again if you want it.

Actually, although the default server menu item is faded, you should still be able to click it, I believe.

This code was added just last night, so keep in mind that it has not been extensively tested

This all seems really cool and interesting. I thank everyone involved in making this happen.

It is my understanding that when you setup the port fowarding through your router and setup a dyndns to connect to your plex server through video plugins, it is a direct stream of the actual file. No transcoding or background processing is done to achive a dedicated stream based on your internet bandwidth (similar to Netflix). Will the Apple TV plugin use the transcoder that is included with plex server to stream movies when source is a remote library? (similar to the Plex App on the Appstore)

Sorry if I am incorrect in any of my info here, this just what I gather.

the current "stable" version does not support non-transcoded playing (ie everything is transcoded), even for local libraries.
In the future, a local library's content will play natively if it can, and everything else will be transcoded.

As for remote libraries, we actually discussed this just today. Bandwidth restrictions might require content to be "scaled down", which will require transcoding. Perhaps we can make this configurable in the atv2plex plugins settings...

the current "stable" version does not support non-transcoded playing (ie everything is transcoded), even for local libraries.In the future, a local library's content will play natively if it can, and everything else will be transcoded.

As for remote libraries, we actually discussed this just today. Bandwidth restrictions might require content to be "scaled down", which will require transcoding. Perhaps we can make this configurable in the atv2plex plugins settings...